USA Data Analysis @

1. USA Data Analysis @ Elliott D. Bloom Particle Astrophysics SLAC, Stanford University elliott@slac.stanford.edu We mainly study photons !

2. Connections: Quarks to the Cosmos Beyond Einstein and the Big Bang

3. Connections…Some of Humanity’s Deepest Questions About the Nature of Our Universe • What powered the big bang? • What is the dark matter that binds together the universe? (GLAST) • What is the dark energy that drives apart the universe? • What is the nature of black holes and gravity beyond Einstein?(GLAST, USA) • Are there hidden spacetime dimensions? (GLAST)

4. NRL: R. Bandyopadhyay, G. Fritz, P. Hertz, M. Kowalski, M. Lovellette (P.S.), P. Ray, L. Titarchuk (& GMU), M. Wolff, K. Wood (P.I.), D. Yentis, W.N. Johnson SLAC/Stanford: E. Bloom (S.U. Lead Co-I), W. Focke, B. Giebels, G. Godfrey, P. Michelson, K. Reilly, M. Roberts, P. SazParkinson, J. Scargle ( & NASA Ames), G. Shabad, D. Tournear USA Collaboration

5. 10” 10” 11.725” • The USA, installed • on top of the ARGOS • satellite. • 5000 lb spacecraft built by Boeing. • Delta-II launch from Vandenberg AFB, CA Feb. 1999. • Orbit: 800 km. altitude, sun synchronous, 98° inclination. • 9 experiments, including USA. • Mission ended November 2001. USA Instrument Dect 2 Dect 1

6. USA DATA SUMMARY

7. USA Top 17 in ks

8. USA AGN Data

9. USA Publications • “Observation of X-ray Variability in the BL Lac Object 1ES 1959+65,” 2002, The Astrophysical Journal, Volume 571, Issue 2, pp. 763-770 ( Found to be TeV emitter after USA publication.) • “Eclipse Timings of the LMXB EXO 0749-676. III. Orbital Period Jitter Observed with the USA Experiment and RXTE,” 2002, The Astrophysical Journal, Volume 575, Issue 1, pp. 384-396 • “USA Experiment Observations of Spectral and Timing Evolution During 2000 Outburst of XTE J1550+564,” 2001, The Astrophysical Journal, Volume 561, Issue 2, pp. L183-L186, • “Observations of GRS 1915+105 from the USA Experiment on ARGOS,” 2001, Astrophysics and Space Science Supplement, Volume 276, pp. 23-24 • “USA Experiment and RXTE Observations of a Low-Frequency Quasi-Periodic Oscillation in XTE J1118+480,” 2000, The Astrophysical Journal, Volume 544, Issue 1, pp. L45-L48 • “USA Experiment on the ARGOS Satellite: a Low Cost Instrument for Timing X-ray Binaries”, 1994, proc. SPIE, Volume 2280, pp. 19-30

10. Accretion Disks in NS/BHCs Most sources discussed here are in a binary system. This allows for the creation of an accretion disk that forms around the compact object. Inner edge of disk: norb ~ 1200Hz(rorb/15km)-3/2 M1.41/2 The behavior of the material inside the accretion disk and the behavior of the material immediately accreted onto the compact object are studied. The physics of the accretion disk leads to interesting outbursts in BHCs lasting for months. The newly accreted material leads to short bursts on neutron stars lasting 10-100s of seconds

11. Noise floor Data Best fit line Theory with no break Theory with a break Upper Limit on Inner edge of BHC Accretion Disk W. Focke, Group K Post doc. Analysis of USA data. The data below are fit to a broken power-law plus noise (A+ Bcos(pf/fNy)), with the slope of the power law above the break locked to f-5 (R. Wagoner's prediction for the disk inner edge signature). The best-fit value of the breakpoint is 756 Hz. The breakpoint was then moved down, while fitting the other parameters, until c2 rose by 2.7, giving a 90% lower limit on the break frequency of 315 Hz. norb ~ 1200Hz(rorb/15km)-3/2 M1.41/2 Expect ~200 Hz for a 10 solar mass non-spinning BH. This implies that the disk extends very close to the hole, and the hole has spin in the direction of the rotation of the accretion disk. The right most line has no break point (Dc2 = 0.8). Thus it is not likely that we have yet seen the inner edge of the disk, thought our best fit suggests the possibility. Systematic errors are not yet included (Crab studies are in process).

12. Types of Non-Quiescent Behavior Short time scale, type I, X-ray bursts were studied with neutron star data to gather information about what luminosity regions they occurred in and BHC data were searched for evidence of these types of bursts. (LEFT) A light curve of a typical type I X-ray burst seen in 4U 1735-445. Longer time scale X-ray outbursts were studied in BHC 4U 1630-472. From these data we can gain information about the source and properties of the accretion. (RIGHT) A light curve showing the 1999 X-ray outburst occurring in 4U 1630-472

13. Searching for X-ray bursts in BHCs Narayan and Heyl Calculated Luminosity ranges where 10 solar mass objects would have X-ray bursts if they did have a surface. In addition, they applied their theory to neutron stars to predict ranges where one would observe bursts in neutron stars. (LEFT) Figure 1 from Narayan & Heyl (2002) displaying regions of instability, shown by dots, in BHCs and Neutron Stars as a function of accretion luminosity (log(Lacc/LEdd)) vs. stellar radius. Top left: 1.4MNS with a base temperature Tin= 108.5 K. Top center: Tin= 108K. Top right: Tin= 107.5 K. Bottom left: 10MBH candidate with a surface, and a base temperature Tin= 107.5 K. Bottom center: Tin= 107 K. Bottom right: Tin= 106.5 K. NS BH

14. USA Type I X-ray Burst Results • Detected nineteen bursts in seven neutron stars • Adding more data from RXTE to push BH limits lower before final publication (editor suggestion). • Applying theoretical framework of NH02 we conclude with USA data alone that BHCs do not have a surface to a Confidence level of 93%

15. Summary USA Data Analysis • Six papers published in archival journals. • Two Papers currently under review. • Six papers currently in draft. • Four PhD’s awarded, with two more scheduled for this year. • Nineteen Posters presented at Astrophysics Conferences.